1. Field of the Invention
The present invention relates to headphones and systems connected to the headphones. More particularly, the present invention relates to headphones with a touch input unit that is designed to detect a one-dimensional coordinate via only one Indium Tin Oxide (ITO) film. The invention is also related to a mobile device that allows for the connection of the headphones.
2. Description of the Related Art
With the rapid development of information and communication technology and semiconductor technology, the use of various types of mobile devices has rapidly increased. Mobile devices employ mobile convergence to provide additional services provided by other types of mobile systems in addition to traditional services. For example, mobile devices generally include the usual communication functions such as voice calling or message transmission, and additional functions such as a TV viewing function (e.g., mobile broadcasting, such as Digital Multimedia Broadcasting (DMB), Digital Video Broadcasting (DVB), etc.), an audio playback function (e.g., MEPG Audio Layer 3 (MP3)), a photographing function, a data communication function, an Internet function, a short-range RF communication function, etc.
Mobile device users can use headphones to listen to music or audio while the mobile device reproduces audio files or broadcasts. Mobile devices of the related art generally allow for the connection of various types of headphones. For example, mobile devices allow for the connection of headphones that have varying configurations, such as 10-pole, 20-pole, etc., according to the mobile device manufactures. In recent years, mobile devices have been equipped with ear jacks supporting headphones with a Φ 3.5 mm 4-pole plug. Accordingly, 4-pole headphones have also been developed to include a button type operating unit such as a volume adjusting key, a call key, etc. When a button key is operated in the button type operation unit of 4-pole headphones, an event occurs such that a level of voltage output to a particular contact (e.g., a microphone contact) has a high degree of variation. To resolve the high degree of variation, conventional 4-pole headphones are configured in such a way that the respective contacts are connected with resistors having different resistances, and such that the microphone contact is connected to a corresponding resistor when the button key is operated. When the button key is operated, the voltage output via the microphone contact is varied according to the resistances allocated to the respective keys. The mobile device detects an output voltage of the microphone contact via the ADC, and identifies the operated key based on the detected level of voltage. However, when conventional 4-pole headphones additionally include button keys for controlling a variety of functions, the button type operating unit must be accordingly large in size. In addition, conventional 4-pole headphones have a limited ability for detecting types of button keys via the level of voltage output from the microphone contact.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention.